Static multi-view display and method using micro-slit scattering elements - Patents.com

Abstract

A static multi-view display and method of operating a static multi-view display includes a micro-slit scattering element configured to reflectively scatter waveguided light from a light guide as a corresponding plurality of directional light beams that encode view pixels of a static multi-view image. The static multi-view display includes a light guide configured to guide light and a plurality of micro-slit scattering elements, each micro-slit scattering element of the plurality of micro-slit scattering elements configured to reflectively scatter a different one of the directional light beams having relative intensities and directions that encode corresponding view pixels of the static multi-view image. Each micro-slit scattering element comprises an inclined reflective sidewall having a tilt angle inclined away from the propagation direction of the guided light resulting in reflective scattering.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS N / A

[0002] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT N / A [Background technology]

[0003] Electronic displays are a nearly ubiquitous medium for conveying information to users of a wide variety of devices and products. The most commonly used electronic displays include cathode ray tubes (CRTs), plasma display panels (PDPs), liquid crystal displays (LCDs), electroluminescent displays (ELs), organic light emitting diode (OLED) and active matrix OLED (AMOLED) displays, electrophoretic displays (EPs), as well as a variety of displays that utilize electromechanical or electrofluidic light modulation (e.g., digital micromirror devices, electrowetting displays, etc.). In general, electronic displays can be classified as either active displays (i.e., displays that emit light) or passive displays (i.e., displays that modulate light provided by another source). Examples of active displays include CRTs, PDPs, and OLED / AMOLEDs. Examples of passive displays include LCDs and EP displays. Passive displays often exhibit attractive performance characteristics, including but not limited to inherently low power consumption, but their inability to emit light may somewhat limit their use in many practical applications. [Brief description of the drawings]

[0004] Various features of examples and embodiments according to the principles described herein can be more readily understood by reference to the following detailed description in conjunction with the accompanying drawings, in which like reference numerals indicate like structural elements and in which:

[0005] [Figure 1] 1 shows a perspective view of an example multi-view display according to an embodiment consistent with principles described herein.

[0006] [Diagram 2] 1 illustrates a graphical representation of angular components of light beams having particular principal angular directions corresponding to view directions of a multi-view display in one example, according to one embodiment consistent with principles described herein.

[0007] [Figure 3A] 1 shows a top view of an example static multi-view display, according to an embodiment consistent with principles described herein.

[0008] [Figure 3B] 1 illustrates a cross-sectional view of a portion of an example static multi-view display, according to an embodiment consistent with principles described herein.

[0009] [Figure 3C] 3C illustrates a perspective view of a portion of the static multi-view display shown in FIG. 3B in one example, according to an embodiment consistent with principles described herein.

[0010] [Figure 3D] 1 shows a perspective view of an example static multi-view display according to an embodiment consistent with principles described herein.

[0011] [Figure 4A] 1 shows a cross-sectional view of a portion of an example static multi-view display, according to one embodiment of principles described herein.

[0012] [Figure 4B] 1 shows a cross-sectional view of a portion of an example static multi-view display according to another embodiment of principles described herein.

[0013] [Figure 4C] 1 shows a cross-sectional view of a portion of an example static multi-view display according to another embodiment of principles described herein.

[0014] [Diagram 5] 1 illustrates a cross-sectional view of a portion of a static multi-view display including a micro-slit scattering element in one example, according to one embodiment consistent with principles described herein.

[0015] [Figure 6] FIG. 1 shows a perspective view of an example curved micro-slit scattering element, according to an embodiment consistent with principles described herein.

[0016] [Figure 7A] 1 shows a top view of a static multiple view display 100 including mitigation of spurious reflections in one example, according to an embodiment consistent with principles described herein.

[0017] [Figure 7B] 1 illustrates a top view of a static multi-view display including mitigation of spurious reflections in one example according to another embodiment consistent with principles described herein.

[0018] [Figure 8A] 1 shows a top view of an example static multi-view display, according to an embodiment consistent with principles described herein.

[0019] [Figure 8B] 8B illustrates a top view of the static multi-view display of FIG. 8A in another example, according to an embodiment consistent with principles described herein.

[0020] [Figure 9] 1 shows a block diagram of an example static multi-view display according to another embodiment consistent with principles described herein.

[0021] [Figure 10] 1 shows a flowchart illustrating a method of operation of a static multi-view display in one example, according to one embodiment consistent with principles described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Particular examples and embodiments have other features in addition to, or in place of, certain features shown in the above-referenced figures, and these and other features are described in detail below with reference to the above-referenced figures.

[0023] Examples and embodiments according to the principles described herein provide for the display of static or quasi-static three-dimensional (3D) or multi-view images. In particular, embodiments consistent with the principles described herein provide for a static multi-view display using a plurality of micro-slit scattering elements configured to emit light comprising a plurality of similar directional light beams that encode view pixels of a multi-view image displayed by the static multi-view display. According to various embodiments, the directional light beams emitted from the micro-slit scattering elements of the plurality of micro-slit scattering elements have individual intensities and directions that correspond to view pixels within a view of the displayed static multi-view image. According to various embodiments, the individual intensities and, in some embodiments, the individual directions of the directional light beams are predetermined or "fixed" by the reflective properties of the micro-slit scattering elements. Thus, the displayed multi-view image may be referred to as a static multi-view image or, in some embodiments, a "quasi-static" multi-view image. Uses of the static multi-view displays described herein include, but are not limited to, mobile phones (e.g., smartphones), watches, tablet computers, mobile computers (e.g., laptop computers), personal computers and computer monitors, automobile display consoles, camera displays, and a variety of other mobile and substantially non-mobile display applications and devices.

[0024] A "multiview display" is defined herein as an electronic display or display system configured to provide different views of a multiview image in different viewing directions. A "static multiview display" is defined herein as a multiview display configured to display a predetermined or fixed (i.e., static) multiview image, albeit as a number of different views. A "quasi-static multiview display" is defined herein as a static multiview display that can be switched between different fixed multiview images or between multiple multiview image states, typically as a function of time. Switching between different fixed multiview images or between multiview image states can provide, for example, a rudimentary form of animation. Furthermore, as defined herein, a quasi-static multiview display is a type of static multiview display. Thus, unless a distinction is necessary for proper understanding, no such distinction is made between a purely static multiview display or image and a quasi-static multiview display or image.

[0025] FIG. 1 illustrates a perspective view of an example multi-view display 10, according to one embodiment consistent with principles described herein. As shown in FIG. 1, the multi-view display 10 includes a screen 12 for displaying a multi-view image to be viewed. The screen 12 may be, for example, a display screen of a phone (e.g., a mobile phone, a smart phone, etc.), a tablet computer, a laptop computer, a computer monitor of a desktop computer, a camera display, or an electronic display of virtually any other device. The multi-view display 10 provides different views 14 of the multi-view image in different view directions 16 relative to the screen 12 (i.e., the multi-view image includes different views 14). The view directions 16 are illustrated as arrows extending in various different principal angular directions from the screen 12, the various views 14 are illustrated as shaded polygonal boxes at the ends of the arrows (i.e., the arrows indicating the view directions 16), and only four views 14 and four view directions 16 are illustrated, all by way of example and not limitation. It should be noted that although the different views 14 are shown in Figure 1 as being above the screen, when a multi-view image is displayed on the multi-view display 10, the views 14 actually appear on or near the screen 12. The views 14 are shown above the screen 12 merely for ease of illustration and are meant to represent viewing the multi-view display 10 from each one of the viewing directions 16 that correspond to a particular view 14.

[0026] A view direction, or equivalently a light beam, having a direction corresponding to a view direction of a multi-view display, generally has a principal angular direction, or simply "direction", given by the definitions herein by the angular components {θ, φ}. The angular component θ is referred to herein as the "elevation component" or "elevation angle" of the light beam. The angular component φ is referred to herein as the "azimuth component" or "azimuth angle" of the light beam. By definition, the elevation angle θ is the angle in a vertical plane (e.g., a plane perpendicular to the plane of the multi-view display screen) and the azimuth angle φ is the angle in a horizontal plane (e.g., a plane parallel to the plane of the multi-view display screen).

[0027] 2 illustrates a graphical representation of angular components {θ, φ} of a light beam 20 having a particular principal angular direction corresponding to a view direction (e.g., view direction 16 in FIG. 1) of a multi-view display in one example, according to one embodiment consistent with principles described herein. Furthermore, the light beam 20, as defined herein, emanates or diverges from a particular point. That is, by definition, the light beam 20 has a central ray associated with a particular origin within the multi-view display. FIG. 2 also illustrates the origin O of the light beam (or view direction).

[0028] In this specification, the term "multi-view" as used in the terms "multi-view image" and "multi-view display" is defined as multiple views representing different viewpoints or including angular parallax between the views of the multiple views. Furthermore, in this specification, the term "multi-view" can explicitly include three or more different views (i.e., at least three views, generally more than three views). Thus, the "multi-view display" as used in this specification can be clearly distinguished from a stereoscopic display that includes only two different views to represent a scene or image. However, it should be noted that while a multi-view image and a multi-view display, by definition in this specification, include three or more views, a multi-view image may be viewed as a stereoscopic pair of images (e.g., on a multi-view display) by selecting to view only two of the views of the multi-view simultaneously (e.g., one view per eye).

[0029] A "multi-view pixel" is defined herein as a collection of scatterers (e.g., micro-slit scattering elements) that represent a "view" pixel in each of a similar plurality of different views of a multi-view display. In particular, a multi-view pixel may comprise individual pixels or a collection of pixels that correspond to or represent view pixels in each of the different views of a multi-view image. Thus, as defined herein, a "view pixel" is a pixel of a particular view of a multi-view display. In some embodiments, a view pixel may include one or more color sub-pixels. Furthermore, the view pixels of a multi-view pixel are so-called "directional pixels" as defined herein in that each of the view pixels is associated with a predefined view direction of a corresponding one of the different views. Furthermore, according to various examples and embodiments, the different view pixels represented by a multi-view pixel may have equivalent or at least substantially similar positions or coordinates in each of the different views.

[0030] As used herein, a "light guide" is defined as a structure that uses total internal reflection to guide light within the structure. In particular, a light guide can include a core that is substantially transparent at the operating wavelength of the light guide. The term "light guide" generally refers to a dielectric light guide, which uses total internal reflection to guide light at the interface between the dielectric material of the light guide and the material or medium that surrounds the light guide. By definition, the condition for total internal reflection is that the refractive index of the light guide is greater than the refractive index of the surrounding medium adjacent the surface of the light guide material. In some embodiments, the light guide can include a coating in addition to or instead of the aforementioned refractive index difference to further promote total internal reflection. The coating can be, for example, a reflective coating. The light guide can be any of a number of light guides, including, but not limited to, one or both of a plate guide or a slab guide and a strip guide.

[0031] Further, the term "plate-like" as applied to a light guide, such as a "plate-like light guide", is defined herein as a piecewise or differentially flat layer or sheet, sometimes referred to as a "slab-like" guide. In particular, a plate-like light guide is defined as a light guide configured to guide light in two substantially orthogonal directions bounded by the top and bottom surfaces (i.e., opposing surfaces) of the light guide. Moreover, by definition herein, the top and bottom surfaces are both separated from each other and may be substantially parallel to each other, at least in the sense of difference. That is, within any different small sections of the plate-like light guide, the top and bottom surfaces are substantially parallel or coplanar. In some embodiments, the plate-like light guide may be substantially flat (i.e., confined to a plane), and thus the plate-like light guide is a planar light guide. In other embodiments, the plate-like light guide may be curved in one or two orthogonal dimensions. For example, the plate-like light guide may be curved in one dimension to form a cylindrical plate-like light guide. However, any curvature has a radius of curvature large enough to ensure that total internal reflection is maintained within the plate-like light guide to guide the light.

[0032] As used herein, a "collimator" is defined as substantially any optical device or apparatus configured to collimate light. According to various embodiments, the amount of collimation achieved by a collimator may vary by a given degree or amount from embodiment to embodiment. Furthermore, a collimator may be configured to provide collimation in one or both of two orthogonal directions (e.g., vertical and horizontal). That is, according to some embodiments, a collimator may include shapes in one or both of two orthogonal directions that provide light collimation.

[0033] As used herein, "collimation factor" is defined as the degree to which light is collimated. In particular, the collimation factor, as defined herein, defines the angular spread of rays in a collimated light beam. For example, a collimation factor σ may specify that the majority of rays in a collimated light beam are within a particular angular spread (e.g., + / - σ degrees around the center or main angular direction of the collimated light beam). According to some examples, the rays of a collimated light beam may have a Gaussian distribution with respect to angle, and this angular spread may be an angle determined by ½ of the peak intensity of the collimated light beam.

[0034] As used herein, a "light source" is defined as a source of light (e.g., a light emitter configured to generate and emit light). For example, a light source may comprise a light emitter, such as a light emitting diode (LED), that emits light when activated or turned on. In particular, as used herein, a light source may be substantially any light source or may include substantially any light emitter, including, but not limited to, one or more of a light emitting diode (LED), a laser, an organic light emitting diode (OLED), a polymer light emitting diode, a plasma-based light emitter, a fluorescent lamp, an incandescent lamp, and substantially any other light source. The light provided by a light source may have a color (i.e., may include a particular wavelength of light) or may have a range of wavelengths (such as white light). In some embodiments, a light source may include multiple light emitters. For example, a light source may include a collection or group of light emitters, where at least one of the light emitters generates light having a color, or equivalently, a wavelength, that is different from the color or wavelength of light provided by at least one other light emitter of the collection or group. The different colors can include, for example, primary colors (eg, red, green, blue).

[0035] As used herein, the article "a" is intended to have its ordinary meaning in the patent art, i.e., "one or more". For example, "microslit scattering element" means one or more microslit scattering elements, and thus "microslit scattering element" means "(a) microslit scattering element" herein. Also, any reference herein to "top", "bottom", "upper", "lower", "up", "down", "front", "back", "first", "second", "left" or "right" is not intended to be limiting herein. As used herein, the term "about", when applied to a value, generally means within the tolerance of the instrument used to generate the value, or may mean plus or minus 10%, plus or minus 5%, or plus or minus 1%, unless otherwise specified. Additionally, as used herein, the term "substantially" means a majority, or nearly all, or all, or an amount within the range of about 51% to about 100%. Additionally, the examples herein are intended to be illustrative only and are presented for discussion purposes and are not intended to be limiting.

[0036] According to some embodiments of the principles described herein, a static multi-view display configured to provide a static or quasi-static multi-view image is provided. FIG. 3A shows a plan view of an example static multi-view display 100 according to one embodiment consistent with the principles described herein. FIG. 3B shows a cross-sectional view of a portion of an example static multi-view display 100 according to one embodiment consistent with the principles described herein. FIG. 3C shows a perspective view of a portion of the static multi-view display 100 shown in FIG. 3B according to one embodiment consistent with the principles described herein. FIG. 3D shows a perspective view of an example static multi-view display 100 according to one embodiment consistent with the principles described herein. While the illustrated static multi-view display 100 is configured to provide a purely static multi-view image, in other embodiments the static multi-view display 100 may be configured to provide a switchable plurality of multi-view images and thus function as (or be) a quasi-static multi-view display 100. For example, the static multiview display 100 may be switchable between different fixed multiview images, or in other words, between multiple multiview image states, as described below. Furthermore, the static multiview display 100 is configured, according to some embodiments, to provide static or quasi-static multiview images showing horizontally-only parallax (HPO) views.

[0037] As shown, the static multi-view display 100 is configured to provide a plurality of directional light beams 102, each of the plurality of directional light beams 102 having an intensity and a main angular direction. Together, the plurality of directional light beams 102 represent or encode various view pixels of a set of views of a multi-view image that the static multi-view display 100 is configured to provide or display. In some embodiments, the view pixels can be organized into multi-view pixels to represent various different views of the multi-view image. FIG. 3B illustrates the directional light beams 102 from a side view, while FIGS. 3C and 3D illustrate the plurality of directional light beams 102 in perspective views. Additionally, FIG. 3C illustrates a set of micro-slit scattering elements that represent multi-view pixels providing a corresponding set of directional light beams 102, directed toward each of the different views of the set of static multi-view images. The set of directional light beams 102 shown in FIG. 3C may represent, for example, directional light beams 102 directed toward different views of a multi-view image.

[0038] FIG. 3D illustrates an example of a plurality of directional light beams 102 that may be provided by the static multi-view display 100. In particular, the directional light beams 102 of the plurality of directional light beams may have different directions and different intensities that represent the directions and intensities of view pixels of a multi-view image displayed by the static multi-view display 100. For example, as shown in FIG. 3D, according to various embodiments, the different directions may correspond to different view directions of the static multi-view display 100, or equivalently, views of the multi-view image. For example, a first set of directional light beams 102' having a first direction may correspond to a first view direction (or first view) of the static multi-view display 100. Similarly, a second set of directional light beams 102" and a third set of directional light beams 102'" may have directions that correspond to a second view direction (or second view) and a third view direction (or third view) of the static multi-view display 100, respectively, as illustrated, and so forth. Also shown in FIG. 3D are a first view 14', a second view 14", and a third view 14'" of a static multi-view image 18 that may be provided by the static multi-view display 100. The illustrated first, second and third views 14', 14", 14"' represent different perspectives of an object and are collectively displayed as a static multi-view image 18 (e.g., equivalent to a static version of the multi-view image having view 14 shown in FIG. 1A). Additionally, different directional light beams 102 represent view pixels of the static multi-view image 18. For example, a first set of directional light beams 102' may represent or encode view pixels of a first view 14', a second set of directional light beams 102" may represent or encode view pixels of a second view 14", and a third set of directional light beams 102'' may represent or encode view pixels of a third view 14'".

[0039] As shown in Figures 3A-3D, the static multi-view display 100 comprises a light guide 110. The light guide 110 is configured to guide light in a propagation direction 103 as guided light 104. Furthermore, in various embodiments, the guided light 104 may have a predetermined collimation factor σ or may be guided according to a predetermined collimation factor σ. For example, the light guide 110 may include a dielectric material configured as a light guide. The dielectric material may have a first refractive index greater than a second refractive index of a medium surrounding the dielectric light guide. The refractive index difference may be configured to promote total internal reflection of the guided light 104 according to one or more guided modes of the light guide 110.

[0040] In some embodiments, the light guide 110 may be a slab or plate light guide (i.e., plate light guide) that includes an elongated, substantially planar sheet of optically transparent dielectric material. The substantially planar sheet of dielectric material is configured to guide the guided light 104 using total internal reflection. According to various examples, the optically transparent material of the light guide 110 may include or be composed of any of a variety of dielectric materials, including, but not limited to, one or more of various types of glasses (e.g., silica glass, alkali aluminosilicate glass, borosilicate glass, etc.) and substantially optically transparent plastics or polymers (e.g., poly(methyl methacrylate) or "acrylic glass" polycarbonate, etc.). In some embodiments, the light guide 110 may further include a cladding layer (not shown) on at least a portion of a surface (e.g., one or both of the top and bottom surfaces) of the light guide 110. According to some examples, the cladding layer may be used to further promote total internal reflection. In particular, the cladding may include a material that has a refractive index greater than the refractive index of the light guide material.

[0041] Furthermore, according to some embodiments, the light guide 110 is configured to guide the guided light 104 according to total internal reflection at non-zero propagation angles between a first surface 110′ (e.g., a “front” or “top” or side) and a second surface 110″ (e.g., a “back” or “bottom” or side) of the light guide 110. In particular, the guided light 104 propagates as a guided light beam by reflecting or “bouncing” at non-zero propagation angles between the first surface 110′ and the second surface 110″ of the light guide 110. In some embodiments, the guided light 104 may include multiple guided light beams representing different colors of light. The different colors of light may be guided by the light guide 110 at each of the different color-specific non-zero propagation angles. Note that for ease of illustration, the non-zero propagation angles are not shown in FIGS. 3A-3D. However, the thick arrow representing the propagation direction 103 depicts the general propagation direction of the guided light 104 along the light guide length in FIG. 3A.

[0042] As defined herein, a "non-zero propagation angle" is an angle relative to a surface of the light guide 110 (e.g., first surface 110' or second surface 110"). Additionally, according to various embodiments, a non-zero propagation angle is greater than zero and less than a critical angle for total internal reflection within the light guide 110. For example, the non-zero propagation angle of the guided light 104 may be between about ten degrees (10°) and about fifty degrees (50°), or between about twenty degrees (20°) and about forty degrees (40°), or between about twenty-five degrees (25°) and about thirty-five degrees (35°). For example, the non-zero propagation angle may be about thirty (30°) degrees. In other examples, the non-zero propagation angle may be about twenty degrees, or about twenty-five degrees, or about thirty-five degrees. Additionally, a particular non-zero propagation angle may be selected (e.g., arbitrarily) for a particular implementation, so long as the particular non-zero propagation angle is selected to be less than a critical angle for total internal reflection within the light guide 110.

[0043] The guided light 104 within the light guide 110 may be introduced or guided into the light guide 110 at a non-zero propagation angle (e.g., about 30-35 degrees). In some embodiments, light may be introduced into the light guide 110 as guided light 104 using structures such as, but not limited to, lenses, mirrors or similar reflectors (e.g., angled collimating reflectors), diffraction gratings, and prisms (not shown), as well as various combinations thereof. In other examples, light may be introduced directly into the input end of the light guide 110 without or substantially without structures (i.e., direct coupling or "butt" coupling may be used). Once guided into the light guide 110, the guided light 104 is configured to propagate along the light guide 110 in a propagation direction 103 that is typically away from the input end.

[0044] Additionally, guided light 104 having a given collimation factor σ may be referred to as a "collimated light beam" or "collimated guided light." As used herein, "collimated light" or "collimated light beam" is generally defined as a beam of light in which the rays of the light beam are substantially parallel to one another within the light beam (e.g., a guided light beam), except as permitted by the collimation factor σ. Additionally, as defined herein, rays that diverge or are scattered from a collimated light beam are not considered to be part of the collimated light beam.

[0045] As shown in Figures 3A-3D, the static multi-view display 100 further comprises a plurality of micro-slit scattering elements 120 distributed across the light guide 110. In particular, the micro-slit scattering elements 120 of the plurality of micro-slit scattering elements 120 are spaced apart or separated from one another by a finite space and represent individual, separate elements across the light guide 110. The plurality of micro-slit scattering elements 120 are configured to reflectively scatter guided light from the light guide 110 as individual ones of the plurality of directional light beams 102 that encode a view pixel of a static multi-view image (e.g., static multi-view image 18). That is, each micro-slit scattering element 120 of the plurality of micro-slit scattering elements is configured to reflectively scatter or provide a different one of the plurality of directional light beams 102 having a relative intensity and direction that encodes a corresponding view pixel of the static multi-view image, i.e., there is a single directional light beam 102 in a single principal angular direction having a single intensity that corresponds to a particular view pixel in one view of the static multi-view image. Thus, there is a one-to-one correspondence between the micro-split scattering elements 120 and view pixels in the views of the multi-view image. According to various embodiments, each of the micro-slit scattering elements 120 includes sloped reflective sidewalls 122 having a slope angle that is angled away from the propagation direction 103 of the guided light 104. Reflective scattering is configured to occur at or achieved by the sloped reflective sidewalls 122 of the micro-slit scattering elements 120.

[0046] According to some embodiments, each slanted reflective sidewall 122 of the micro-slit scattering element 120 has a predetermined reflectance characteristic configured to determine the relative intensity of the directional light beam 102 provided by the micro-slit scattering element 120. The relative intensity of the directional light beam 102 then encodes the intensity or brightness of the view pixel corresponding to the micro-slit scattering element 120. For example, the predetermined reflectance characteristic can include a length or depth of the slanted reflective sidewall 122. In another example, the predetermined reflectance characteristic can include a surface reflectance of the slanted reflective sidewall 122. In some examples, the predetermined reflectance characteristic can include both a depth and a surface reflectance. In some embodiments, the micro-slit scattering element 120 can have a predetermined rotation angle with respect to the propagation angle of the guided light 104. In these embodiments, the predetermined rotation angle is configured to determine the direction of the directional light beam scattered by the micro-slit scattering element 120 that encodes the corresponding view pixel, i.e., the direction encodes the direction of the view pixel.

[0047] In some embodiments, one microslit scattering element 120 of the plurality of microslit scattering elements may be disposed on or at a surface of the light guide 110. For example, the microslit scattering element 120 may be disposed at the emitting surface (e.g., first surface 110') of the light guide 110 as shown in FIG. 3B. In this example, one microslit scattering element 120 of the plurality of microslit scattering elements extends into the interior of the light guide 110 toward the second surface 110" of the light guide 110. In another example, the microslit scattering element 120 may be disposed on or at the second surface 110" opposite the emitting surface or first surface 110' of the light guide 110. In this example, the microslit scattering element 120 of the plurality of microslit sub-elements may extend into the interior of the light guide 110 away from the second surface 110".

[0048] In other embodiments, the micro-slit scattering element 120 may be located within the light guide 110. In particular, the micro-slit scattering element 120 may be located between or spaced apart from both the first surface 110' and the second surface 110" of the light guide 110 in these embodiments. For example, the micro-slit scattering element 120 may be provided on a surface of the light guide 110 and then covered by a layer of light guide material, effectively embedding the micro-slit scattering element 120 within the light guide 110.

[0049] In yet another embodiment, the micro-slit scattering element 120 may be disposed in an optical material layer located on a surface of the light guide 110. In some of these embodiments, the surface of the optical material layer may be an emitting surface, and one of the micro-slit scattering elements 120 may extend away from the emitting surface toward the light guide surface. In some embodiments, the optical material layer located on the surface of the light guide 110 may be index matched to the index of refraction for the material of the light guide 110 to reduce or substantially minimize reflection of light at the interface between the light guide 110 and the material layer. In other embodiments, the material may have a higher index of refraction than the index of refraction of the light guide material. Such a higher index material layer may be used, for example, to improve the brightness of the emitted light, including the directional light beam 102.

[0050] According to some embodiments, a microslit scattering element 120 of the plurality of microslit scattering elements may include multiple microslit sub-elements 124. In particular, according to various embodiments, the guided light portion may be collectively reflectively scattered by the multiple microslit sub-elements 124 of the microslit scattering element 120 using reflection or reflective scattering. According to various embodiments, each microslit sub-element 124 of the plurality of microslit sub-elements may comprise a sloped reflective sidewall, as defined herein, having a slope angle that is sloped away from the propagation direction of the guided light. In some embodiments, the sloped reflective sidewall of the microslit sub-element 124 may be substantially similar to the sloped reflective sidewall 122 of the microslit scattering element 120. That is, the sloped reflective sidewall 122 of the microslit scattering element 120 may include one or more sloped reflective sidewalls of the microslit sub-elements 124. Furthermore, the presence of multiple microslit sub-elements 124 within one or more of the microslit scattering elements 120 may facilitate granular control of the reflective scattering properties of the emitted light, and thus the directional light beam 102 of the emitted light.

[0051] FIG. 4A illustrates a cross-sectional view of a portion of an example static multi-view display 100, according to one embodiment of principles described herein. As shown in FIG. 4A, the static multi-view display 100 comprises a light guide 110 with a micro-slit scattering element 120 disposed on a first surface 110′ of the light guide 110. The micro-slit scattering element 120 illustrated in FIG. 4A extends into the light guide 110 and comprises a number of micro-slit sub-elements 124. As shown, the guided light 104 is reflected by the slanted reflective sidewalls 122 of the micro-slit scattering element 120, including the slanted reflective sidewalls 124-1 of the micro-slit sub-elements 124, and exits the emission surface (e.g., the first surface 110′) of the light guide 110 as emitted light comprising the directional light beam 102. In particular, the guided light 104 may be reflected by one or more of the slanted reflective sidewalls 124-1 of the micro-slit sub-elements 124 of the micro-slit scattering element 120, as illustrated. 4A , the sloped reflective sidewalls 122 of the microslit scattering element 120, or equivalently the sloped reflective sidewalls 124-1 of the microslit sub-elements 124, have a slope angle α that is sloped away from the propagation direction 103 of the guided light 104. In some embodiments, the depth d of the microslit scattering element 120 including the microslit sub-element(s) 124 may be approximately equal to the pitch p (or spacing) between adjacent microslit sub-elements 124 within the microslit scattering element 120.

[0052] FIG. 4B illustrates a cross-sectional view of a portion of an example static multi-view display 100 according to another embodiment of the principles described herein. As shown in FIG. 4B, the static multi-view display 100 includes a light guide 110 and a micro-slit scattering element 120 including a plurality of micro-slit sub-elements 124. However, in FIG. 4B, the micro-slit scattering element 120 is disposed within the light guide 110 between the first and second surfaces 110′, 110″. Similar to FIG. 4A, the guided light 104 is illustrated in FIG. 4B as being reflected by the sloped reflective sidewalls 122 of the micro-slit scattering element 120 (e.g., the sloped reflective sidewall 124-1 of the first micro-slit sub-element 124) and exiting the emission surface (first surface 110′) of the light guide 110 as emitted light including the directional light beam 102.

[0053] FIG. 4C illustrates a cross-sectional view of a portion of a static multi-view display 100 in one example according to another embodiment of the principles described herein. As illustrated, the static multi-view display 100 comprises a light guide 110 having an optical material layer 112 disposed on a first surface 110′ of the light guide 110. The micro-slit scattering element 120 illustrated in FIG. 4C is located within the optical material layer 112. Additionally, as illustrated, the micro-slit scattering element 120 includes a plurality of micro-slit sub-elements 124 each having an inclined reflective sidewall 122, 124-1. In FIG. 4C, the micro-slit sub-elements 124 of the plurality of micro-slit sub-elements, and also the micro-slit scattering element 120, extend away from an emission surface that includes a surface of the optical material layer 112 and toward the first surface 110′ of the light guide 110. Additionally, the depth of the micro-slit sub-elements 124, or equivalently, the depth of the micro-slit scattering element 120, may be comparable to a thickness or height h of the optical material layer 112, for example as illustrated. FIG. 4C shows guided light 104 passing from light guide 110 into optical material layer 112 and then being reflected by first sloping reflective sidewall 122 of microslit sub-element 124 to provide emitted light comprising directional light beam 102.

[0054] It should be noted that while Figures 4A-4C depict a microslit scattering element 120 including multiple microslit subelements 124, each of these figures could similarly depict the microslit scattering element 120 in isolation by simply considering one of the depicted microslit subelements 124. It should also be noted that while each of the microslit subelements 124 of the microslit scattering element 120 depicted in Figures 4A-4C have a similar size and shape, in some embodiments (not shown), the microslit subelements 124 of the multiple microslit subelements, or equivalently the microslit scattering elements 120 of the multiple microslit scattering elements, may be different from one another within each plurality. For example, the microslit subelements 124 may have one or more of different sizes, different cross-sectional profiles, and even different orientations (e.g., rotations relative to the guided light propagation direction) within and across the microslit scattering element 120. Similarly, the microslit scattering elements 120 may have one or more of different sizes, different cross-sectional profiles, and even different orientations (e.g., rotations relative to the guided light propagation direction) within and across the plurality of microslit scattering elements. In particular, according to some embodiments, at least two microslit sub-elements 124 of the plurality of microslit sub-elements or two microslit scattering elements 120 of the plurality of microslit scattering elements may have different reflective scattering profiles from each other.

[0055] According to some embodiments, the sloped reflective sidewall 122 of the microslit scattering element 120, or equivalently the sloped reflective sidewall 124-1 of the microslit sub-elements 124 of the plurality of microslit sub-elements, is configured to reflectively scatter a portion of the guided light 104 according to total internal reflection (i.e., due to the difference in refractive index of materials on either side of the sloped reflective sidewall 122). That is, the guided light 104 having an angle of incidence at the sloped reflective sidewall 122 less than the critical angle is reflected by the sloped reflective sidewall 122 into a directional light beam 102 of emitted light.

[0056] In some embodiments, the slope angle α of the sloped reflective sidewall 122, 124-1 is between zero degrees (0°) and about forty-five degrees (45°) relative to the surface normal of the emitting surface of the light guide 110 (or equivalently the static multi-view display 100). In some embodiments, the slope angle α of the sloped reflective sidewall 122, 124-1 is between ten degrees (10°) and about forty degrees (40°). For example, the slope angle α of the sloped reflective sidewall 122, 124-1 may be about twenty degrees (20°), or about thirty degrees (30°), or about thirty-five degrees (35°), relative to the surface normal of the emitting surface of the light guide 110.

[0057] According to various embodiments, the tilt angle α is selected in conjunction with the non-zero propagation angle of the guided light 104 to achieve a target angle of the directional light beam 102 of emitted light. Furthermore, the selected tilt angle α may be configured to preferentially scatter light in the direction of the emission surface of the light guide 110 (e.g., first surface 110') and away from the surface of the light guide 110 opposite the emission surface (e.g., second surface 110"). That is, the sloped reflective sidewalls 122, 124-1 may, in some embodiments, provide little or substantially no scattering of the guided light 104 in a direction away from the emission surface.

[0058] In some embodiments, the slanted reflective sidewalls 122, 124-1 can include a reflective material configured to reflectively scatter a portion of the guided light 104. For example, the reflective material can be a layer of a reflective metal (e.g., aluminum, nickel, gold, silver, chromium, copper, etc.) or a reflective metallic polymer (e.g., polymer aluminum) coated on the slanted reflective sidewalls 122, 124-1. In another example, the interior of the microslit scattering element 120 or the microslit sub-elements 124 can be filled or substantially filled with a reflective material. In some embodiments, the reflective material filled in the microslit scattering element 120 or the microslit sub-elements 124 can provide reflective scattering of the guided light portion at the slanted reflective sidewalls.

[0059] In some embodiments (e.g., as shown in Figures 4A-4C), the first sidewall of the microslit scattering element 120, or the first sidewall of one of the microslit subelements 124 of the plurality of microslit subelements, may have a slope angle substantially similar to the slope angle of the second sidewall of the microslit scattering element 120 or microslit subelement 124. That is, the opposing sidewalls may be substantially parallel to one another. In other embodiments, the first sidewall may have a slope angle different from the slope angle of the second sidewall, and the first sidewall is a sloped reflective sidewall 122.

[0060] FIG. 5 illustrates a cross-sectional view of a portion of a static multi-view display 100 including a micro-slit scattering element 120 in one example, according to one embodiment consistent with principles described herein. As illustrated, the micro-slit scattering element 120 is illustrated on a first surface 110′ of the light guide 110, with a first sidewall 122-1 of the micro-slit scattering element 120 representing a slanted reflective sidewall having a slant angle α. Additionally, a second sidewall 122-2 of the micro-slit scattering element 120 has a slant angle different from the slant angle α of the first sidewall 122-1, as illustrated. In particular, the second sidewall 122-2 illustrated in FIG. 5 has a slant angle of approximately zero degrees (0°), i.e., the slant angle of the second sidewall 122-2 is substantially parallel to a surface normal of the first surface 110′ of the light guide 110, as illustrated.

[0061] In some embodiments, a micro-slit scattering element of the plurality of micro-slit scattering elements may have a curved shape in a direction perpendicular to the guided light propagation direction 103. In particular, the curved shape may be in a direction perpendicular to the propagation direction 103 and in a plane parallel to the surface of the light guide 110. According to some embodiments, the curved shape may be configured to control the radiation pattern of the scattered light in the plane perpendicular to the guided light propagation direction.

[0062] FIG. 6 illustrates a perspective view of an example curved micro-slit scattering element 120 according to an embodiment consistent with principles described herein. As shown, the curved micro-slit scattering element 120 is located within the light guide 110 and has a curved shape that is convex with respect to the propagation direction 103 of the guided light. The convex curved shape of the micro-slit scattering element 120 may be used to increase the spread of the reflected scattered light in the xy direction, as shown. In another example (not shown), the curved shape of the micro-slit scattering element 120 may be concave with respect to the propagation direction 103, for example, to reduce the spread of the reflected scattered light. Furthermore, in some embodiments, the radius of curvature of the curved shape may be preferentially selected to control the amount of spread of the reflected scattered light. The curved shape may be equally applied to the micro-slit sub-elements (not shown).

[0063] 3A-3D, according to some embodiments, the static multi-view display may further comprise a light source 130 at an input location on the light guide 110. As shown, the light source 130 may be configured to provide guided light 104 including multiple guided light beams (shown in dashed lines in FIGS. 3A and 3D) having different radial directions 118 from one another into the light guide 110, i.e., the guided light 104 has a "fan" pattern of propagation within the light guide 110. In these embodiments, different ones of the multiple micro-slit scattering elements 120 may be configured to align with and scatter the guided light 104 from different ones of the multiple guided light beams having different radial directions 118 within the light guide 110. For example, the light source 130 may be located adjacent an edge or side 114 of the light guide 110, as shown.

[0064] In particular, as shown in FIGS. 3A and 3D , light emitted by the light source 130 may be configured to enter the light guide 110 and propagate radially as multiple guided light beams away from the input location 116, across or along the length of the light guide 110. Furthermore, the individual guided light beams of the multiple guided light beams have different radial directions from each other due to the radial pattern of propagation away from the input location 116. For example, the light source 130 may be butt-coupled to the side 114. A butt-coupled light source 130 may facilitate the introduction of light in a fan pattern, for example, to provide different radial directions of the individual guided light beams of the guided light 104. According to some embodiments, the light source 130 may be, or at least approximate, a “point” light source at the input location 116 such that the individual guided light beams of the guided light 104 propagate along different radial directions 118 (i.e., as multiple guided light beams).

[0065] In some embodiments, the input location 116 of the light source 130 is on the side 114 of the light guide 110, approximately at the center or approximately at the middle of the side 114. In particular, in FIGS. 3A and 3D , the light source 130 is shown at an input location 116 that is approximately at the center (e.g., the middle) of the side 114 (i.e., the "input side") of the light guide 110. Alternatively (not shown), the input location 116 may be at the center or away from the center of the side 114 of the light guide 110. For example, the input location 116 may be at a corner of the light guide 110. For example, the light guide 110 may have a rectangular shape (e.g., as shown), and the input location 116 of the light source 130 may be at a corner of the rectangular light guide 110 (e.g., a corner of the input side 114).

[0066] In various embodiments, the light source 130 may include substantially any light source (e.g., light emitter), including, but not limited to, one or more light emitting diodes (LEDs) or lasers (e.g., laser diodes). In some embodiments, the light source 130 may comprise a light emitter configured to generate substantially monochromatic light having a narrowband spectrum denoted by a particular color. In particular, the color of the monochromatic light may be a primary color of a particular color space or color model (e.g., RGB color model). In other examples, the light source 130 may be a substantially broadband light source configured to provide substantially broadband or polychromatic light. For example, the light source 130 may provide white light. In some embodiments, the light source 130 may comprise a plurality of different light emitters configured to provide light of different colors. The different light emitters may be configured to provide light having different color-specific, non-zero propagation angles of guided light corresponding to each of the different colors of light.

[0067] In some embodiments, the guided light beam of the guided light 104 generated by coupling light from the light source 130 into the light guide 110 may not be collimated, or at least may not be substantially collimated. In other embodiments, the guided light beam may be collimated in a vertical direction (i.e., the guided light 104 may be collimated in a direction perpendicular to the first and second surfaces 110′, 110″ of the light guide 110). Thus, in some embodiments, the static multi-view display 100 may comprise a “vertical” collimator (not shown) between the light source 130 and the light guide 110. Alternatively, the light source 130 may further comprise a vertical collimator. The vertical collimator is configured to provide a vertically collimated guided light beam into the light guide 110. In particular, the vertical collimator is configured to receive substantially uncollimated light from one or more of the light emitters of the light source 130 and convert the substantially uncollimated light into vertically collimated light. That is, a vertical collimator is, by definition, configured to provide collimation in a plane substantially perpendicular to the direction of propagation of the guided light 104 (e.g., a "vertical" plane). In particular, vertical collimation can provide a collimated guided light beam having a relatively narrow angular spread in a plane perpendicular to the surface of the light guide 110 (e.g., first or second surface 110', 110")). According to various embodiments, the vertical collimator can include any of a variety of collimators, including, but not limited to, a lens, a reflector or mirror (e.g., a tilted collimating reflector), or a diffraction grating (e.g., a diffraction grating-based barrel collimator) configured to collimate light from the light source 130.

[0068] Furthermore, in some embodiments, the collimator can provide either vertically collimated light with a non-zero propagation angle or vertically collimated light that is collimated according to a predefined collimation factor, or both. Furthermore, when different color light emitters are used, the collimator can be configured to provide either collimated light with different color-specific non-zero propagation angles or collimated light with different color-specific collimation factors, or both. The collimator, in some embodiments, is further configured to transmit the collimated light to the light guide 110 for propagation as a guided light beam.

[0069] In some embodiments, the use of collimated or non-collimated light may affect the multi-view image that may be provided by the static multi-view display 100. For example, if the guided light beam of the guided light 104 is collimated in the light guide 110, the emitted directional light beam 102 may have a relatively narrow or limited angular spread in at least two orthogonal directions. Thus, the static multi-view display 100 may provide a multi-view image having multiple different views in an array having two different directions (e.g., x-direction and y-direction). However, if the guided light beam of the guided light 104 is not substantially collimated, the multi-view image may achieve view parallax but may not achieve a complete two-dimensional array of different views. In particular, if the guided light beam is not collimated (e.g., along the z-axis), the multi-view image may provide a different multi-view image that exhibits "parallax 3D" or "full parallax" when rotated about the y-axis (e.g., as shown in FIG. 1A). On the other hand, for example, if the static multi-view display 100 is rotated about the x-axis, the multi-view image and its views may remain substantially unchanged or the same since the directional light beam 102 of the multiple directional light beams has a wide angular variation range in the yz-plane. Thus, the multi-view image provided may be "horizontal parallax only" (HPO), realizing an array of views in only one direction instead of two.

[0070] In some embodiments, various sources of spurious reflections of the guided light 104 in the static multiview display 100 may be mitigated, and in some cases substantially eliminated, particularly where those spurious reflection sources may cause light beams to be emitted in unintended directions, which in turn may cause unintended images to be generated by the static multiview display 100. Examples of various potential sources of spurious reflections include, but are not limited to, sidewalls of the light guide 110, which may cause secondary reflections of the guided light 104. Reflections from various sources of spurious reflections in the static multiview display 100 may be mitigated by any of several techniques, including, but not limited to, absorption and controlled redirection of the spurious reflections.

[0071] FIG. 7A illustrates a plan view of a static multi-view display 100 including spurious reflection mitigation in one example, according to one embodiment consistent with principles described herein. FIG. 7B illustrates a plan view of a static multi-view display 100 including spurious reflection mitigation in one example, according to another embodiment consistent with principles described herein. In particular, FIGS. 7A and 7B illustrate a static multi-view display 100 comprising a light guide 110, a plurality of micro-slit scattering elements 120, and a light source 130. Also shown are a plurality of guided light beams of guided light 104, with at least one guided light beam 104′ of the plurality incident on a sidewall 114a, 114b of the light guide 110. Potential spurious reflections of the guided light beam 104′ by the sidewall 114a are indicated by dashed arrows representing the reflected guided light beam 104″.

[0072] In FIG. 7A, the static multi-view display 100 further comprises an absorbing layer 119 on the sidewall 114b of the light guide 110. The absorbing layer 119 is configured to absorb incident light from a guided light beam, e.g., guided light beam 104′. The absorbing layer may comprise substantially any light absorber, including, but not limited to, black paint applied to the sidewall 114b. As shown in FIG. 7A, by way of example and not limitation, the absorbing layer 119 is applied to the sidewall 114b, while the sidewall 114a is devoid of the absorbing layer 119. The absorbing layer 119 blocks and absorbs the incident guided light beam 104′, effectively preventing or mitigating the generation of potential spurious reflections from the sidewall 114b. Meanwhile, the guided light beam 104′ incident on the sidewall 114a is reflected, generating a reflected guided light beam 104″, shown by way of example and not limitation.

[0073] FIG. 7B illustrates the mitigation of spurious reflections using a controlled reflection angle. In particular, the light guide 110 of the static multiple view display 100 illustrated in FIG. 7B includes sloped sidewalls 114a, 114b (i.e., sloped sidewalls). The sloped sidewalls have a slope angle configured to block an incident guided light beam (e.g., guided light beam 104') and preferentially direct the reflected guided light beam 104" substantially away from the micro-slit scattering element 120. Thus, the reflected guided light beam 104" is not scattered from the light guide 110 as an unintended directional light beam. The slope angles of the sidewalls 114a, 114b may be in the xy plane as illustrated. In other examples (not shown), the slope angle of sidewalls 114a, 114b may be in another plane, e.g., the xz plane, to direct the reflected guided light beam 104" outward from the top or bottom edge of the light guide 110; for example, the reflected guided light beam 104" is illustrated in FIG. 7B as being directed outward from the top edge of the light guide 110, by way of example and not limitation. Note that FIG. 7B shows sidewalls 114a, 114b including a slope along only a portion thereof, by way of example and not limitation.

[0074] According to some embodiments, the static multiview display 100 may comprise a plurality of light sources 130 that are laterally offset from one another. By laterally offsetting the light sources 130 of the plurality of light sources, differences in the radial orientation of the various guided light beams of the guided light 104 at or between individual micro-slit scattering elements 120 may be produced. According to some embodiments, this difference may facilitate the realization of animation of the displayed multiview image. Thus, the static multiview display 100 may, in some embodiments, be a "quasi-static" multiview display.

[0075] FIG 8A shows a plan view of an example static multi-view display 100 according to one embodiment consistent with principles described herein. FIG 8B shows a plan view of the static multi-view display 100 of FIG 8A according to another example embodiment consistent with principles described herein. The static multi-view display 100 shown in FIG 8A and FIG 8B comprises a light guide 110 having a plurality of micro-slit scattering elements 120. Additionally, the static multi-view display 100 further comprises a plurality of light sources 130 configured to separately provide guided light beams of guided light 104 that are laterally offset from one another and have different radial directions 118 from one another, as shown.

[0076] In particular, Figures 8A and 8B show a first light source 130a at a first input location 116a and a second light source 130b at a second input location 116b on a side 114 (input side) of the light guide 110. The first and second input locations 116a, 116b are laterally offset or shifted from one another along the side 114 (i.e., in the x-direction) to achieve a lateral offset of the respective first and second light sources 130a, 130b. Furthermore, each of the first and second light sources 130a, 130b of the plurality of light sources 130 provides different plurality of guided light beams 104a, 104b of guided light 104 having different radial directions from one another. For example, as shown in Figures 8A and 8B, respectively, a first light source 130a may provide a first plurality of guided light beams 104a having a first set of different radial directions 118a, and a second light source 130b may provide a second plurality of guided light beams 104b having a second set of different radial directions 118b. Furthermore, the first and second plurality of guided light beams 104a, 104b generally have sets of different radial directions 118a, 118b that differ from one another as a set due to the lateral offset of the first and second light sources 130a, 130b, as shown.

[0077] Thus, the multiple micro-slit scattering elements 120 emit directional light beams that represent different multi-view images that are shifted relative to one another in view space (e.g., angularly shifted in view space). Thus, by switching between the first light source 130a and the second light source 130b, the static multi-view display 100 can provide an "animation" of the multi-view image, such as a time-series animation. In particular, by sequentially illuminating the first and second light sources 130a, 130b for different consecutive time intervals or times, the static multi-view display 100 may be configured to shift the apparent position of the multi-view image, for example, for different times. According to some embodiments, this shift in apparent position achieved by animation can represent an example of operating the static multi-view display 100 as a quasi-static multi-view display to provide multiple multi-view image states.

[0078] 9 illustrates a block diagram of an example static multi-view display 200 according to another embodiment consistent with principles described herein. According to various embodiments, the static multi-view display 200 is configured to display a static multi-view image having different views in different view directions. In particular, directional light beams 202 of light emitted by the static multi-view display 200 may be used to display the multi-view image and correspond to pixels of different views (i.e., view pixels).

[0079] As shown in FIG. 9, the static multi-view display 200 comprises a light guide 210. The light guide 210 is configured to guide light in a propagation direction as a plurality of guided light beams 204. According to various embodiments, the guided light beams 204 of the plurality of guided light beams have or are guided in a fan-shaped pattern. In particular, within the fan-shaped pattern, according to some embodiments, the guided light beams 204 of the plurality of guided light beams have different radial directions from each other and appear to emanate from a common point of origin. In various embodiments, the guided light beams may be guided within the light guide according to total internal reflection. For example, the light guide 210 may be a plate-like light guide configured to guide light from its light-entering edge as the guided light beams 204. In some embodiments, the light guide 210 of the static multi-view display 200 may be substantially similar to the light guide 110 described above with respect to the static multi-view display 100.

[0080] The static multi-view display 200 shown in FIG. 9 further comprises a plurality of micro-slit scattering elements 220. According to various embodiments, the micro-slit scattering elements 220 of the plurality of micro-slit scattering elements are spaced apart from one another across the light guide 110. The micro-slit scattering elements 220 of the plurality of micro-slit scattering elements are configured to emit a directional light beam 202 representing a view pixel of the static multi-view image. Each of the micro-slit scattering elements 220 of the plurality of micro-slit scattering elements comprises a slanted reflective sidewall and is configured to emit or provide a directional light beam 202 from a portion of the guided light beam 204 of the plurality of guided light beams having an intensity and direction corresponding to the relative intensity and view direction of the view pixel of the static multi-view image. In particular, the directional light beam 202 provided by each of the micro-slit scattering elements 220 encodes a different one of the view pixels of the static multi-view image. According to various embodiments, the directional light beams 202 emitted or provided by reflective scattering from the slanted reflective sidewalls have different principal angular directions. According to various embodiments, different principal angular directions of the directional light beam correspond to respective view directions of different view pixels of the static multi-view image. In some embodiments, the micro-slit scattering elements 220 of the static multi-view display 200 may each be substantially similar to the micro-slit scattering elements 120 of the static multi-view display 100 described above. For example, the micro-slit scattering element 220 may include a plurality of micro-slit sub-elements substantially similar to the micro-slit sub-elements 124 described above. According to various embodiments, each micro-slit scattering element 220, and likewise each micro-slit sub-element, comprises an inclined reflective sidewall having a tilt angle tilted away from the propagation direction of the guided light.

[0081] In some embodiments, the sloped reflective sidewall of each micro-slit scattering element 220 has a predetermined reflective characteristic determined by one or both of a depth of the sloped reflective sidewall and a surface reflectivity of the surface of the sloped reflective sidewall configured to determine the relative intensity of the directional light beam corresponding to the micro-slit scattering element. In some embodiments, each micro-slit scattering element 220 of the plurality of micro-slit scattering elements can have a predetermined rotation angle with respect to a radial direction of the guided light beam 204 corresponding to the micro-slit scattering element 220. According to some embodiments, the predetermined rotation angle can be configured to determine the direction of the directional light beam 202.

[0082] In some embodiments, the micro-slit scattering element 220 of the plurality of micro-slit scattering elements is disposed on or below the emitting surface of the light guide (or equivalently the static multi-view display 200). In these embodiments, the micro-slit scattering element 220 extends into the interior of the light guide away from the emitting surface. In some embodiments, one micro-slit scattering element 220 of the plurality of micro-slit scattering elements is disposed in a light guide material layer that is located on a surface of the light guide. In these embodiments, the surface of the light guide material layer may be the emitting surface of the static multi-view display 200, and the micro-slit scattering element 220 may extend toward the surface of the light guide 210 away from the emitting surface.

[0083] 9, the static multi-view display 200 further comprises a light source 230. The light source 230 is configured to provide a plurality of guided light beams 204 having different radial directions into the light guide 210. In some embodiments, the light source 230 may be substantially similar to the light source 130 of the static multi-view display 100 described above. For example, the light source 230 may be butt-coupled to an edge of the light guide 210 to approximate a point source.

[0084] In some embodiments, the guided light may be collimated (e.g., vertically) according to a predetermined collimation factor. In some embodiments, the radiation pattern of the emitted light, including the directional light beam 202, is a function of the predetermined collimation factor of the guided light. For example, the predetermined collimation factor may be substantially similar to the predetermined collimation factor σ described above with respect to the static multiview display 100.

[0085] According to some embodiments of the principles described herein, a method of operation of a static multi-view display is provided. FIG. 10 shows a flowchart of a method 300 of operation of a static multi-view display in an example according to one embodiment consistent with the principles described herein. As shown in FIG. 10, the method 300 of operation of a static multi-view display includes a step 310 of directing light in a propagation direction along a length of a light guide as guided light. In some embodiments, the light may be directed 310 at a non-zero propagation angle. The guided light may also be collimated. In particular, the guided light may be collimated according to a predetermined collimation factor. In some embodiments, the step 310 of directing light may provide guided light having a fan-shaped pattern with guided light beams having radial directions different from each other. According to some embodiments, the light guide may be substantially similar to the light guide 110 described above with respect to the static multi-view display 100. In particular, according to various embodiments, the light may be directed according to total internal reflection within the light guide. Similarly, the predetermined collimation factor and non-zero propagation angles may be substantially similar to the predetermined collimation factor σ and non-zero propagation angles described above with respect to the light guide 110 of the static multi-view display 100 .

[0086] As shown in FIG. 10, the method 300 of operating a static multi-view display further includes a step 320 of reflecting a portion of the guided light from the light guide as a corresponding plurality of directional light beams using a plurality of micro-slit elements. According to various embodiments, the directional light beams encode view pixels of the static multi-view image. In addition, each micro-slit scattering element of the plurality of micro-slit scattering elements provides a different one of the directional light beams having a relative intensity and direction of a corresponding view pixel of the static multi-view image. In particular, according to various embodiments, there is a one-to-one correspondence between each of the micro-slit scattering elements, the scattered directional light beams provided by the micro-slit scattering elements, and the view pixels of the static multi-view image encoded by the directional light beams.

[0087] In some embodiments, the micro-slit scattering elements of the plurality of micro-slit scattering elements are substantially similar to the micro-slit scattering elements 120 described above with respect to the static multiple view display 100. In particular, the micro-slit scattering elements each comprise an inclined reflective sidewall having a slope angle inclined away from the propagation direction of the guided light.

[0088] In some embodiments, the sloped reflective sidewalls reflectively scatter the light according to total internal reflection to reflect a portion of the guided light out of the light guide to provide a directional light beam, hi other embodiments, the microslit scattering elements of the microslit scattering element array further comprise a reflective material adjacent to and coating the sloped reflective sidewalls of the plurality of microslit sub-elements.

[0089] In some embodiments, the slope angle of the sloped reflective sidewalls may be from about zero degrees (0°) to about forty-five degrees (45°) relative to the surface normal of the emission surface of the light guide in some embodiments. In some embodiments, the slope angle may be selected in conjunction with a non-zero propagation angle of the guided light to preferentially scatter light toward the emission surface of the light guide and away from the surface of the light guide opposite the emission surface.

[0090] In some embodiments (not shown), the method 300 of operating a static multiview display further includes providing light guided by the light guide with a light source, the light source providing guided light comprising a plurality of guided light beams having different radial directions within the light guide. In these embodiments, different micro-slit scattering elements of the plurality of micro-slit scattering elements are aligned with and reflected from guided light from different guided light beams of the plurality of guided light beams having different radial directions within the light guide. In some embodiments, the light source may be substantially similar to the light source 130 of the static multiview display 100 described above.

[0091] Thus, examples and embodiments of static multi-view displays and methods of operating a static multi-view display have been described that use micro-slit elements with slanted reflective sidewalls to provide emitted light comprising directional light beams with directions and intensities corresponding to different view pixels of a multi-view image. It should be understood that the above examples are merely illustrative of some of the many specific examples that represent the principles described herein. Clearly, those skilled in the art can readily devise numerous other configurations without departing from the scope defined by the claims that follow.

Claims

1. 1. A static multi-view display, comprising: a light guide configured to guide light as a guided wave; a plurality of micro-slit scattering elements distributed throughout the light guide and configured to reflectively scatter the guided light from the light guide as a corresponding plurality of directional light beams that encode view pixels of a static multi-view image, each micro-slit scattering element of the plurality of micro-slit scattering elements configured to reflectively scatter a different one of the directional light beams having a relative intensity and direction that encodes a corresponding view pixel of the static multi-view image; Equipped with A static multi-view display, wherein each micro-slit scattering element comprises an inclined reflective sidewall having a tilt angle tilted away from the propagation direction of the guided light.

2. 2. The static multiple view display of claim 1, wherein the sloped reflective sidewalls of each micro-slit scattering element have predetermined reflective properties configured to determine the relative intensities of the directional light beams encoding the corresponding view pixels.

3. The static multiple view display of claim 2 , wherein the predetermined reflective properties of the sloped reflective sidewalls include a depth of the sloped reflective sidewalls.

4. The static multiple view display of claim 2 , wherein the predetermined reflective property of the sloped reflective sidewall comprises a surface reflectance of the sloped reflective sidewall.

5. 2. The static multiple view display of claim 1 , wherein the micro-slit scattering elements have a predetermined rotation angle with respect to a propagation angle of the guided light, the predetermined rotation angle being configured to determine a direction of the directional light beam scattered by the micro-slit scattering element that encodes the corresponding view pixel.

6. The static multiple view display of claim 1 , wherein a micro-slit scattering element of the plurality of micro-slit scattering elements includes a plurality of micro-slit sub-elements, each micro-slit sub-element having the sloped reflective sidewall.

7. 2. The static multiple view display of claim 1 , wherein one micro-slit scattering element of the plurality of micro-slit scattering elements is disposed on an emitting surface of the light guide, the micro-slit scattering element extending into the light guide, away from the emitting surface.

8. 2. The static multiple view display of claim 1 , wherein one micro-slit scattering element of the plurality of micro-slit scattering elements is disposed in a light guide material layer located on a surface of the light guide, the surface of the light guide material layer being an emission surface, and the micro-slit scattering element extends away from the emission surface toward the light guide surface.

9. 9. A static multiple view display as claimed in claim 8, wherein the refractive index of the light guide material layer located on the surface of the light guide is greater than the refractive index of the material of the light guide.

10. 2. The static multiple view display of claim 1, wherein the sloped reflective sidewalls of the micro-slit scattering elements of the plurality of micro-slit scattering elements comprise a reflective material configured to reflectively scatter the waveguided light.

11. 2. The static multiple view display of claim 1, wherein the slope angle of the sloped reflective sidewalls is between 0 degrees and about 45 degrees relative to a surface normal to an emission surface of the light guide, the slope angle being configured to preferentially scatter light towards the emission surface of the light guide and away from a surface of the light guide opposite the emission surface.

12. 2. The static multi-view display of claim 1 , wherein one micro-slit scattering element of the plurality of micro-slit scattering elements has a curved shape in a direction orthogonal to the propagation direction of the guided light and parallel to a plane of a surface of the light guide, the curved shape being configured to control a radiation pattern of scattered light in a plane orthogonal to the propagation direction of the guided light.

13. The static multiple view display of claim 1 , wherein the guided light is collimated according to a predetermined collimation factor, and a radiation pattern of the directional light beam is a function of the predetermined collimation factor of the guided light.

14. 2. The static multiple view display of claim 1, further comprising a light source at an input position on the light guide, the light source configured to provide the guided light into the light guide comprising a plurality of guided light beams having different radial directions from one another, and different ones of the plurality of micro-slit scattering elements aligned with guided light from different ones of the plurality of guided light beams having the different radial directions within the light guide and configured to scatter the guided light.

15. 1. A static multi-view display, comprising: a light guide configured to guide light as a plurality of guided light beams in a sector pattern, the guided light beams of the plurality of guided light beams having different radial directions within the light guide; a plurality of micro-slit scattering elements configured to emit directional light beams representing a view pixel of a static multi-view image, each micro-slit scattering element of the plurality of micro-slit scattering elements including a sloped reflective sidewall and configured to provide a directional light beam from a portion of a guided light beam of the plurality of guided light beams having an intensity and direction corresponding to a relative intensity and view direction of a view pixel of the static multi-view image corresponding to the micro-slit scattering element; A static multi-view display comprising:

16. 16. The static multiple view display of claim 15, wherein the sloped reflective sidewall of each of the micro-slit scattering elements has a predetermined reflective characteristic determined by one or both of a depth of the sloped reflective sidewall and a surface reflectivity of a surface of the sloped reflective sidewall configured to determine a relative intensity of the directional light beam corresponding to the micro-slit scattering element, and each of the micro-slit scattering elements of the plurality of micro-slit scattering elements has a predetermined rotation angle with respect to a radial direction of a guided light beam corresponding to the micro-slit scattering element configured to determine a direction of the directional light beam.

17. 16. The static multiple view display of claim 15, wherein one micro-slit scattering element of the plurality of micro-slit scattering elements is disposed either above the emitting surface of the light guide or below the emitting surface, the micro-slit scattering element extending away from the emitting surface into the interior of the light guide.

18. 16. The static multiple view display of claim 15, wherein one micro-slit scattering element of the plurality of micro-slit scattering elements is disposed in a light guide material layer located on a surface of the light guide, the surface of the light guide material layer being an emission surface of the static multiple view display, and the micro-slit scattering element extends away from the emission surface towards the surface of the light guide.

19. 16. The static multiple view display of claim 15, further comprising a light source configured to provide the plurality of guided light beams having different radial directions within the light guide.

20. 1. A method of operating a static multi-view display, comprising: Guiding light in a propagation direction as guided light along a length of a light guide; reflecting the guided light from the light guide as a corresponding plurality of directional light beams using a plurality of micro-slit scattering elements, the directional light beams encoding view pixels of a static multi-view image, each micro-slit scattering element of the plurality of micro-slit scattering elements providing a different one of the directional light beams having a relative intensity and direction of a corresponding view pixel of the static multi-view image; Including, wherein the micro-slit scattering elements each comprise sloped reflective sidewalls having a slope angle angled away from the propagation direction of the guided light.

21. 21. The method of claim 20, wherein the inclined reflective sidewalls reflectively scatter light according to total internal reflection to reflect a portion of the guided light out of the light guide to provide the directional light beam.

22. 21. A method of operating a static multiple view display as described in claim 20, wherein the slope angle of the sloped reflective sidewalls is between 0 degrees and about 45 degrees relative to a surface normal to an emission surface of the light guide, the slope angle being selected in conjunction with a non-zero propagation angle of the guided light to preferentially scatter light towards the emission surface of the light guide and away from a surface of the light guide opposite the emission surface.

23. providing light guided by the light guide using a light source, the light source providing the guided light into the light guide comprising a plurality of guided light beams having different radial directions; 21. A method of operating a static multiple view display as described in claim 20, wherein different ones of the plurality of micro-slit scattering elements are aligned with different ones of the plurality of guided light beams having different radial directions within the light guide and reflect guided light from the different guided light beams.

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